| Alzheimer's Disease(AD)is characterized by progressive cognitive decline usually beginning with important in through ability to form recent menories,but inevitable affecting all intellectual functions and leading to complete dependence for basic functions of daily life,and premature death.Neuropathologically,AD is characterized by the aberrant accumulation and deposition of misfolded proteins.In particular,extracellular neuritic plaques made of aggregated forms of neurotoxic amyloid ?-peptide(A?)and intracellular deposits of abnormally phosphorylated tau protein and chronic neuroinflammation which can cause neuron death are considered as key hallmarks of AD brain.The number of people with AD and other dementias will grow each year as the size and population of the world aged 60 years and older continue to increase.It will be a heavy economic burden on the whole society.None of the pharmacologic treatments available today for AD slows or stop the malfunction and death of neurons in the brain that cause AD symptoms and eventually make the disease fatal.Therefore,to explore an economic and effective drug is of great significance.It has become increasingly apparent that neuroinflammation plays a significant role in the pathophysiology of AD.Many soluble mediators are released by activated microglia and neurons during neuroinflammatory diseases,and have the potential to influence synaptic transmission.In particular,tumor necrosis factor ?(TNF-?)and interleukin 1?(IL-1?)are all potential candiates for such an action.In the same time,researchers have found that pro-inflammatory cytokines TNF-? and IL-1? were the most effective activating stimuli for nuclear factor kappa B(NF-?B)in neurons of those examined.In turn,NF-?B signaling can upregulate TNF-?,IL-1?,inducible nitric oxide synthase(i NOS)and toll-like receptor,and then forming a vicious cycle of chronic inflammatory reaction.A number of studies have investigated the potential role for aspirin in the treatment and prevention of AD,although at this stage,its therapeutic potential has not been proven.Epidemiological investigations showed that individuals who used high-dose aspirin exhibited lower rates of AD and improved maintenance of cognition than those who did not use the drug.Given the anti-inflammatory effects of aspirin,it is speculated that it can reduce the risk of AD may be associated with its anti-inflammatory effects.In this study,we use aspirin in the neurons injuried models of AD which are made with A?,then explore the pro-inflammatory cytokines of TNF-? and IL-1?,as well as NF-?B /p65 and total protein phosphorylated inhibitor protein ? of nuclear factor kappa B(p I?B-?)to study the influence of aspirin on them.In order to provide a new way for the treatments of AD.Objective It has become increasingly apparent that neuroinflammation plays a significant role in the pathophysiology of AD.To determine the effect of aspirin on the clinical treatment of AD and investigate the role of NF-?B pathway in this process,we use A? to make neurons injuried model of AD.After intervention of aspirin,we will test the level of IL-1? and TNF-? in the supernatant,and the expression of NF-?B /p65 and p I?B-? in neurons.Methods(1)Harvest hippocampus of fetal rats and cut it into pieces,after digesting and filtering the tissues,plant it into 6 well plate.(2)Observe and record the neuronal growthon the 2nd,3rd,4th and 5th day.Identify neurons with neuron specificity enolization fluorescent staining method on the 7th day and calculate the purity.(3)Divided the neurons randomly into 4 groups,that is,A? treatment group(20 umol/L A?25-35),low dose aspirin group(50 umol/L aspirin and 20 umol/L A?25-35),high dose aspirin group(100 umol/L aspirin and 20 umol/L A?25-35),and the blank control group.After 48 hours' treatment,the levels of IL-1? and TNF-? in the supernatant were measured with ELISA,and the expression level of NF-?B/p65 and p I?B-? with Western blotting.Results(1)Compared with control group,A? treatment remarkably resulted in the highest levels of TNF-? and IL-1?(P<0.01),the second is low dose aspirin group(P<0.01)and third is high dose aspirin group(P=0.02 and P<0.01).The expression of NF-?B/p65 and p I?B-? are also increased in A? group(P <0.01),the expression of NF-?B/p65 in low dose aspirin group is slightly increased(P=0.01),but there was no significant difference in the expression of p I?B-?(P=0.61).There were no statistical differences in the expression of NF-?B/p65 and p I?B-?(P=0.13 and 0.77).(2)Compared with A? group,low dose aspirin group had lower levels of TNF-? and IL-1?(P<0.01),as well as the expression of NF-?B/p65 and p I?B-?(P<0.01).The levels of TNF-? and IL-1? in high dose Asp group were also decreased(P<0.01),as well as the expression of NF-?B/p65 and p I?B-?(P<0.01).(3)There were no statistical differences between the low and high dose aspirin groups in the comparison of TNF-?,IL-1?,NF-?B/p65 and p I?B-?(P=0.36,0.58,0.19 and 0.82).Conclusions A? group increased levels of TNF-? and IL-1?,upregulated the expression of NF-?B/p65 and p I?B-?,indicating that there was obvious inflammatory response in A? group and NF-?B was activated to translocate to the nucleus.In the other hand,the low and high dose aspirin groups had lower levels of TNF-? and IL-1?,as well as the expression of NF-?B/p65 and p I?B-?,suggested that inflammatory response was suppressed and the activation of NF-?B was also inhibited.In summary,A? could have induced higher levels of pro-inflammatory cytokines TNF-? and IL-1? by activating NF-?B signaling pathway.And aspirin could have decreased levels of TNF-? and IL-1? by suppressing the activation of NF-?B which could attenuate neuronal inflammatory injuries.A strong association between inflammation and AD has been suggested and there is a promise in anti-inflammatory therapy of AD.Since there were no statistical differences between the low and high dose aspirin groups,we recommend a lower dose of aspirin in animal experiments to avoid the possible gastrointestinal side effects of high dose aspirin. |
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